Cherry-pick PRs to 1.3.x branch and release v1.3.0-beta.3 (#1491)

* Celostats reliability (#1487)

Description
Improve reliability from the ethstats module

The connectionWrapper was cherrypicked from go-ethereum upstream:
ethereum/go-ethereum@82a9e11 (ethereum/go-ethereum#21404)

Other changes
Validator injecting its version to the proxy stats chunk

Tested
Manually in a local testnet

Related issues
Fixes #1395
Fixes #1397
Backwards compatibility
Yes

* Skip GPM and other checks for transactions whose gas limit exceeds what's left in the block

* Change default tx pool GlobalSlots back to 4096.

The decrease to 2048 was due to inefficiencies in the tx pool which have now been fixed, so this sets it back to its original value.

* Release v1.3.0-beta.3

Co-authored-by: Gaston Ponti <[email protected]>

core/tx_pool.go

@@ -196,7 +196,7 @@ var DefaultTxPoolConfig = TxPoolConfig{
 	PriceBump:  10,
 
 	AccountSlots: 16,
-	GlobalSlots:  2048,
+	GlobalSlots:  4096,
 	AccountQueue: 64,
 	GlobalQueue:  1024,